Republican Sen. John McCain called on Wednesday for a dramatic increase in U.S. airstrikes against Islamic State targets in Iraq and said the attacks should also extend into Syria.

McCain told Reuters that the beheading of American journalist James Foley by Islamic State militants should serve as a turning point for President Barack Obama’s deliberations on how to deal with the group.

“First of all, you’ve got to dramatically increase the airstrikes. And those airstrikes have to be devoted to Syria as well,” McCain said in a telephone interview.

Of the video of Foley’s beheading, McCain said: “I don’t think there’s any doubt that this horrible video on the Internet is bound to have an impact on the American people. The nature of the brutality of this organization has been brought home by this.”

McCain said hitting Islamic State targets in Syria is necessary because the militants have captured military equipment in the Iraqi city of Mosul which they seized in June and moved it into enclaves inside Syria.

“We have to defeat them, not stop them,” he said.

The Arizona senator also said the United States should arm Iraqi Kurds and help arrange a reconciliation between Shiites and Sunnis in Iraq.